Ignition distributor



Filed Jan. 16, 1959 4 tst 1 l8 l6 T52 550 v |o a i INVENTOR w l 2 ERNST A. LONGENECKER $15 .3 ATTORNEY y 1963 E. A. LONGENECKER 3,091,672

IGNITION DISTRIBUTOR 4 Sheets-Sheet 2 Filed Jan. 16, 1959 INVENTOR ERA/57" A. LONGE/VECKER ATTORNEY E. A. LONGENECKER 3,091,672

IGNITION DISTRIBUTOR May 28, 1963 4 Sheets-Sheet 3 Filed Jan. 16, 1959 INVENTOR ERN5T A. LONGE/VECKEQ ATTORNEY y 28, 1953 E. A. LONGENECKER 3,091,672

IGNITION DISTRIBUTOR 4 Sheets-Sheet 4 Filed Jan. 16, 1959 INVENTOR ATTORNEY ERNST A. LONGENECKER United States Patent 9 3,il9l,672 IGNITION DESTUTOR Ernst A. Longenecker, 411 S. Higby St, Jackson, Mich. Filed Jan. 16, 1959, Ser. No. 787,253 18 Claims. (Cl. 206-31) The present invention pertains to ignition components for internal combustion engines and particularly relates to improved distributor elements wherein portions of the distributor circuit consist of separate units which may be replaced and interchanged without special skills or tools. The present invention is a continuation-in-part of my US. Patent No. 2,923,785.

As is common knowledge most ignition difliculties in internal combustion engines arise from the wearing, pitting and break down of the-breaker points which comprise a part of the primary ignition circuit and as these contact breaker points wear, erratic engine performance results. The correction of such a condition necessitates replacement of contact points and at the time of such'replacemerit it is also advisable to install a new breaker point condenser to insure proper performance. In distributor constructions now in common use the breaker points are in the form of a switch unit which includes a cam follower wherein the unit is affixed to a support plate and adjusted thereto to provide the proper contact point spacing as the cam follower rides on the high point of the distributor cam lobes. The new condenser is separately installed on the support plate and the electrical connections made to the breaker points and the primary ignition circuit. This type of construction is troublesome in that tools are required for the installation of new breaker points and more particularly special skill and knowledge is required in that the spacing of the contacts is critical. As it often happens that ignition trouble due to breaker point malfunction prevents the motor from operating at all and as such breaker point failure may occur without warning the motorist may experience great inconvenience due to his inability to remedy the trouble himself.

The adjustment of the breaker point gap when installed in accordance with conventional practice is usually measured with a fe'eler gage inserted between the contacts and it is often difiicult to obtain an accurate gap measurement with this type of gage. Preferably a dial indicator gage should be used and it is one of the purposes of the invention to provide a method in which breaker points may be readily adjusted by such a gage.

To overcome the primary objections to conventional distributor construction it is the purpose of the invention to provide a distributor breaker point-condenser-cam unit which is preadjusted to the proper contact gap and distributor drive shaft relationship and which may be installed in a pre-adjusted distributor merely by removing the old unit and placing the new unit in position without the use of tools or special skills. Such a unit construction is disclosed in my above mentioned copending application, however, it is the purpose of the instant invention to provide a construction and method of pre-setting which is particularly adaptable to civilian vehicles and which lends itself to mass production, ease of manufacture, and economical replacement.

It is also a purpose of the invention to provide a distributor having economically manufactured components which are positive in their operation and may be assembled in the distributor with a minimum of housing machining. As manufacturers of internal combustion engines usually produce a number of different engine models varying in horsepower, cost, size, etc. it is desirable if the manufacturer may obtain a distributor of given construction which may readily be adjusted and used with all engine models and another purpose of the invention isto provide a distributor which is versatile enough for such use.

3,091,672 Patented May 28, 1963 It is thus one of the objects of the invention to provide a breaker point unit for internal combustion engine ignition systems which may be pre-set to provide proper timing when used with a pre-set distributor whereby the contact gap, condenser and cam are mounted upon a common support plate and replaced and installed as a unit without the use of tools or special skills.

Another object of the invention is to provide a timing unit employed in the primary circuit of an ignition system which includes a replaceable cam, contact points and condenser as a unit which is mounted as to be sensitive to centrifugal and vacuum regulated spark advance structure.

A further object of the invention is to provide a distributor wherein the components thereof are economically manufactered, are readily installed and removed from the distributor housing and which reduces the number 0 components over conventional practice.

Yet another object of the invention is to provide a fixture on which a breaker point-condenser-cam unit may be pre-adjusted to provide optimum performance and a fixture for pre-adjusting a distributor for receiving such a unit.

Another object of the invention is to provide a timing unit for ignition systems which may be pre-set to a given ad ustment and may be installed and used in a distributor without additional adjustment yet, if desired, permits conventional adjustment of the breaker points.

Yet a further object of the invention is to provide a fixture for pre-adjusting a distributor timing unit in accordance with the invention employing a test circuit which includes the circuit of the unit to be tested.

Yet another object of the invention is to provide a breaker point unit'which is held in position by biased clamps which prevent assembly of the distributor unless the clamps are in operative position and in which an improved structure for maintaining the distributor in assembled relation is provided.

A still further object of the invention is to provide an improved vacuum spark advance structure in ignition distributors and to provide improved means for maintaining 1saaid spark advance structure mounted on the distributor These and further objects of the invention arising from the structural details of the described embodiments will become apparent from the following description and accompanying drawings wherein:

FIG. 1 is a cross sectional view of a distributor employi ng the concepts of the invention with the distributor cap in position,

FIG. 2 is a top plan view of the distributor of FIG. 1 with the cap removed,

FIG. 3 is a partial cross sectional elevational view taken along line TIL-III of FIG. 2,

FIG. 4 is a cross sectional plan view of the distributor with the breaker point plate and mounting plate removed and the vacuum advance mechanism shown in section,

FIG. 5 is a detail sectional elevation of the bearing block support plate,

FIG. 6 is a detail sectional elevation of a bearing block taken along line VIVI of FIG. 4,

FIG. 7 is a elevational view, partly in section, of the distributor of the invention with the cap in place showing details of the shaft retaining means, cap spring and spring holder,

FIG. 8 is an elevational view of the vacuum advance diaphragm housing taken along the line VIII-VIII of FIG. 4,

FIG. 9 is a plan view of the distributor showing the centrifugal governor advance mechanism taken along line IX-IX of FIG. 3,

FIG. is an enlarged plan view of a portion of FIG. 9 showing the weight movement limiting means.

FIG. 11 is a sectional elevational view of the weight movement limiting means taken along the line Xl-XI of FIG. 10,

FIGS. 12 and 13 are elevational views of the upturned centrifugal weight spring anchorages used with the low and high speed weights respectively,

FIG. 14 is an elevational plan view of the distributor in accord with the invention similar to FIG. 2, however showing a dual ignition breaker point plate installed in lieu of the single breaker point plate,

FIG. 15 is an elevational sectional view of the distributor timing fixture as mounted on a distributor,

FIG. 16 is a top plan view of FIG. 15,

FiG. 17 is a top plan view of the breaker point plate timing fixture with .a breaker unit in position for testing and timing,

FIG. 18 is a detail sectional view of the breaker point plate fixture hold down taken along the line XVIII- XVIII of FIG. 17, and

FIG. 19 is a sectional elevational view of the breaker point timing fixture taken along the line XIX-XIX of FIG. 17.

It will be understood that although the distributor hereinafter described may be employed with any internal combustion engine employing a gear driven distributor, many of the features disclosed may be incorporated in direct driven types of distributors with little or no modific-ation.

The distributor of the invention takes the general form of gear driven distributors having a cylindrical housing 10 from which depends a shaft housing 12 on which is formed a mounting flange 14. A cylindrical drive shaft 16 is journaled within housing 12 on sintered porous bearings 18 and a drive gear, not shown, is afiixed to the lower end of the shaft 16 as viewed in FIG. 7. The distributor is mounted to the engine in the conventional manner, e.g. the flange 14 is afiixable to the motor block by clamping means such that the housing 10 may be rotatably positioned relative to the block and locked in position. The drive gear afiixed to shaft 16 meshes with a gear usually mounted on the cam shaft and in this manner insures a predetermined relationship between the engine components sequence of operation and the distributor operation.

The shaft 16 is provided at the upper regions with a stepped diameter 20 and a further reduced portion 22 extends upwardly to provide support and guidance for other distributor components as will be later described. The lower region of shaft 16 is grooved at 24 to receive an annular snap ring 26, FIG. 7, which may bear against a thrust washer member adjacent the lower bearing 18. A Weight mounting plate 28 is press fitted to the shaft step 20 and may engage a thrust washer resting on the upper end of upper bearing 18. Thus the shaft 16 is axially positioned by the plate .28 and the snap ring 26, an economical and simplified means to accomplish this purpose.

The weight mounting plate 28 includes a pair of pivot studs 30 affixed thereon in opposed diametrical relation to the shaft 16 and a low speed weight 32 and a high speed Weight 34 are pivotally mounted to the studs 30. The center of gravity of weights 32 and 34 do not coincide with the radial line interconnecting the center of shaft 16 and pivots 30, therefore the weights will tend to swing out upon rotation of plate 23. The plate 28 includes at each end an upturned spring anchorage projection, the low speed anchorage being designated 36 and the high speed anchorage 38. The projection 36 is provided with a central hole 40 which receives one end of spring 42, the other end being aflixed to weight 32. The projection 38 is recessed on each side at 44 to receive one end of spring 46 which is also connected to weight 34. The dimensions of the loops in the ends of the springs, the spring diameter and hole 40 diameter are such as to prevent the wrong spring from being assembled to the improper anchorage.

A stud 48 is mounted in weight 32 and projects upwardly therefrom, FIG. 3, and a stud 50 of a larger upper diameter is similarly mounted in the weight 34. These studs project through slots 52 and 54 formed in the centrifugal advance plate 56. The slots 52 and 54 extend in a radial direction and the former is of less width than the latter as these slots are only a few thousandths of an inch greater in Width than the cooperating stud. This relationship prevents misassembly of the plate 56 to the weight studs.

Therefore as the weight mounting plate 28 is rotated the weights 32 and 34 will rotate therewith and have a tendency to pivot outwardly against the force of the attached springs due to centrifugal force. Such weight movement causes the studs 48 and 50 to move in an are about the pivot studs 30 causing an attendant angular rotation of the advance plate 56. The weight 32 will move first as spring 42 is of lighter tension than spring 46 and hence ignition spark advance sensitive to engine r.p.m. is provided through both low and high speed ranges as the rotation of advance plate 56 drives the breaker point cam as will be later apparent. The high speed weight 34 is provided with limit means whereby the degree of spark advance at high speeds may be regulated. This limiting means comprises a pivot 58 frictionally rotatable mounted in the weight and provided with a slot whereby the pivot 58 may be rotated by a screw driver. Pivot 58 is formed with a downward extending eccentric portion 60 which, when the weight 34 pivots outwardly, may engage the edge of the weight mounting plate, see FIGS. 10 and 11, limiting the weight movement. Thus, by rotating pivot 58 adjustment of the degree of weight 34 movement may be varied and hence the maximum spark advance regulated. Indicia is imprinted on the weight to indicate the setting of the pivot 58. This adjustable centrifugal advance limiting feature permits the distributor to be employed with a wide variety of engine types and sizes without necessitating separate advance plates for each different engine model as is the common practice.

The advance plate 56 is affixed to and drives a cylindrical support sleeve 62 which is rotatably journaled on shaft portion 22 and rests on a thrust washer supported on plate 28. Sleeve 62 is provided at the upper end with a radial key projection 64, FIG. 3, which drives the breaker point cam as will be hereinafter described.

As best shown in FIGS. 1 and 3 the housing 10 is interiorly shouldered at 66 and the bearing block mounting plate 68 rests thereon. To lock plate 68 in position, a pair of diametrically downward projecting inclined portions 70 are formed on plate 68 by slitting or deforming and screws 71, threaded through the housing 10, engage portions 70 forcing plate 68 downwardly and locking the plate in the proper position.

Centrally the plate 68 is provided with a concentric opening through which the sleeve 62 projects and intersecting this opening are three radial slots 72 having parallel sides defined by removing rectangular portions of the plate. The slots 72 are adapted to receive bearing blocks 74 which are formed of a material such as sintered iron and are of a configuration as shown in FIGS. 5 and 6. As observed, blocks 74 are provided with longitudinal recesses 76 on two sides thereof for receiving the sides of the slots 72 and the inner upper portions are formed with an undercut surface 78 facing outwardly and a notch 80 facing inwardly. The dimensions of two of the slots 72 are such the blocks 74 must be forced into the slot, the edges thereof actually dig into the recesses 76 and two of the blocks are thus firmly located equal distances from the axis of shaft 16. The third block 74 is slidingly supported with its slot 72 and upon installing the ring spring 82 under compression within notches 80 this movable block will be biased radially outward.

The bearing mounting plate 68 is notched at 84 to provide clearance for the vacuum advance structure and a ground wire 86 is attached thereto for connection to the breaker point plate as later described.

The purpose of the bearing mounting plate 68 is to provide the means for rotatably mounting the support plate 88. Support plate 88 is of a circular disc configuration having a central coaxial aperture having a beveled periphery 90. By biasing the slidable bearing block 74 inwardly the plate 88 may be placed on the bearing blocks such that the undercut surfaces 78 engage the periphery 90 to hold the support plate 88 in place, note FIG. 3. The plate 88 is maintained parallel to plate 68 by resting on the locating surface 92 formed on each bearing block.

A pair of diametrically opposed hold down clamps are mounted on the support plate 88 for the purpose of maintaining the breaker point plate thereon. The clamps are represented at 94 and comprise stamped members having a latch surface 96 defined thereon, FIG. 1, and an outwardly extending handle portion 9 8. The clamps 94 extend through openings defined in plate 88 and are mounted on leaf springs 100 aflixed to the underside of plate 88 by a rivet 102 formed by displacing metal of the plate 88. The handle portion 98 projects above the rim of the housing and when the clamps are open, e.g. released from the breaker point plate, the handle 98 overlaps the rim and prevents the distributor cap from being positioned on the housing 10.

A pin .104 is aflixed within support plate 88, FIG. 7, and extends both above and below the plane thereof. This pin orients the breaker point plate within the distributor and is also coupled to the vacuum advance means as will be later apparent.

A breaker point mounting plate 106 is adapted to be removable mounted on the support plate 88. The mounting plate 106 and the components assembled and mounted thereon form a basic part of the invention as this is the member which may be quickly installed or removed whereby a new pro-timed breaker point unit is readily available. On plate 106 are mounted a breaker point assembly generally indicated at 108, a condenser 110 and a cam 112. The breaker points assembly may be of conventional design and are attached to the plate 106 by screws 114 whereby the points may be adjusted relative to the plate 106 in the known manner. Triangular shaped openings 116 are formed in plate 106 to align with a similar opening in the breaker point assembly whereby a screw driver inserted into these openings and twisted will adjust the breaker point assembly relative to the plate 186 and the point gap may be thus regulated. Assembly 188 includes a terminal 118 onto which the primary lead 120 may be affixed. Lead 120 passes through a rubber, water-tight grommet 122 affixed in an opening in housing 10.

The condenser 110 is also afiixed to the breaker point plate 106 by a screw or other conventional means and is interconnected to the breaker point circuit by a lead 124 which may take the form of a leaf or wire. To insure that plate 106 is always grounded a tit is formed on the plate to which the ground Wire 86 may be attached.

The cam 112 is mounted on the plate 106 by means of a reduced portion 126 extending through a central opening in the plate and the bottom of portion 126 is flanged to prevent the cam from disengaging from the opening. The lower end of cam 112 is formed with a radial notch 128 which receives key projection 64 of sleeve 62 thereby driving the cam. The cam is also centrally bored to closely receive the shaft portion 22 as transverse deflection of the cam is prevented by the shaft portion 22, however the cam may rotate relative thereto in response to centrifugal spark advance compensations. Cam 112 is provided with a number of lobes which correspond to the number of engine cylinders and is formed with a keyway 130 where- 6 by a rotor 132 having a key may be affixed to the cam and oriented thereto in the well known manner.

A pair of upturned projections 134 are diametrically formed on the plate 106 adjacent the periphery thereof by slitting and bending. These projections, see FIG. 1, cooperate with the latch surface 96 of clamps 94 as shown and permit the clamps to firmly hold the breaker point plate 106 in engagement with the support plate 88 yet provide easily operable means for quickly installing or removing the breaker point plate.

The plate 106 must be accurately oriented to the support plate 88 and other distributor components to insure consistent and accurate timing irregardless of how often the breaker point plate 106 is changed and this orientation is achieved by a tang 136 formed on plate 106 by slitting and upwardly offsetting the tongue above the plane of the plate as observed in FIG. 7. Tang 136 is formed with a neck 138 of reduced Width by punching openings 140 in plate 106 adjacent the neck during the slitting operation. An elongated radial extending slot 142 is formed in tang 136 and is of a width a few thousandths of an inch greater than thediameter of pin 104 whereby, when assembled, the pin 104' is received within slot 142 and accurately determines the angular relationship between the plate 186 and support plate 88.

i It Will thus be appreciated that by removing ground wire 86, lead 124 and moving the clamps 94 radially away from the drive shaft axis to disengage from projections 134 the breaker point plate 106 may be removed from the distributor, removing the breaker point assembly 108, condenser 110 and cam 112 as a unit. To install a new plate 186 and the components mounted thereonit is merely necessary to correct the ground and lead wires as described, align cam 112 over shaft portion 22 such that notch 128 meshes with key projection 64 and drop plate 186 on the support plate 88 such that pin 104 extends through slot 142. Clamps 94 are then moved inwardly to engage surfaces 96 with the ends of projections 134 to lock plates 186 and 88 together. The resiliency of springs 100 maintains the clamps in firm engagement with the projections and insures a tight, vibration resistant connection.

To provide proper ignition timing at all speeds and loads it is known to employ an automatic vacuum controlied spark advance in conjunction with the centrifugal governor advance means. In accordance with the invention the vacuum spark advance takes the form best illustrated in FIG. 4 wherein two diaphragm housing components 144 and 146 are assembled together by folding a flange 148 of housing 146 over a flange 150 of housing 144, and a diaphragm 152 of rubber or other suitable material is sealingly sandwiched therebetween. The housings 144-146 are preferably formed of stampings which may be easily and economically manufactured and housing 144 is formed at one end with a bell fitting 154 onto which a rubber vacuum line, not shown, may be aflixed and a spring clamp may compress the hose onto the fitting 154. The vacuum line communicates with the carburetor throat in the known manner.

The diaphragm 152 is backed on both sides by washers 156 and a projection 158 formed on link 160 acts as a rivet end and extends through central holes in the diaphragm and washers to aflix the diaphragm, washers and link together as a unit. A spring 162 of pre-determined length and characteristics engages an annular shoulder of housing 144 and the adjacent washer 156 to bias the diaphragm toward the housing 10.

Link 160 is provided with an elongated slot 164 and an offset arm in which a hole 166 is defined. The housing 146 is preferably formed with a rectangular axial projecting end 168 which fits within a complementary shaped recess 178 within the housing 10. A spring pin, e.g. a transversely contractable pin, is inserted Within holes in housing 10 and end 168 to maintain the end within recess 170 and the diaphragm housing aflixed to the distributor.

Pin 172 also extends through the slot 164 and in this capacity acts to limit the axial movement of the link 160. The hole 166 is of a size to closely receive the lower end of pin 104, FIG. 7, and through this connection transfers movement of the diaphragm 152 under vacuum variations into a rotational adjustment of the support plate 88 and breaker point plate 166 mounted thereon. The bearing blocks 74 insure that this rotational movement of support plate 88 will be concentric to the axis of shaft 16.

A distributor cap 174, molded of a dielectric phenolic compound, is attached to the housing to receive the spark plug leads and distribute the secondary ignition voltage in the known manner. Cap 174 includes a plurality of spark plug terminals 176 and a central secondary circuit coil terminal 17 8. A carbon resistor 130 connects to terminal 178 forming a part of the cap and a spring biased contact 182 mounted on the rotor 132 completes the circuit from the coil terminal 178 to the spark plug terminals 176 in accordance with the rotational position of cam 112 in the known manner. The underside of the cap 174 is preferably provided with annular spark barrier ridges 184 to resist voltage leakage and spark jumping. The rotor is provided with a similar upstanding ridge barrier for the same purpose.

It is common to employ spring clips mounted to the distributor housing to hold the cap in position and such clips are preferably used with the invention, however, novel clip holding means are used to afiix the clips to the housing. By forming a pair of diametrically opposed holes 186 of rectangular configuration on the underside of the housing 11 FIG. 7, a spring clip 183 may be affixed to the housing merely by inserting the lower end thereof into the hole. To assemble the clip in this manner the lower end of the clip is bent at 199 to define a portion 192 and rebent at 194 adjacent the end 196 of the clip. The normal distance between portions 192 and 194 is greater than the opening of the holes 186 whereby upon inserting these portions into hole 186 portion 194 will be deflected toward 192 and a clearance shoulder 198 within holes 186 permits the portion 194 to deflect out such that the end 196 engages shoulder 198 and prevents withdrawal of the clip from the housing 10. The upper end of clip 188 is formed in the conventional fashion and cooperates with a land on the cap. Thus the clips 188 may be affixed to housing 10 Without the use of extra pins, hinges or other components and assembly of the clips to the housing is accomplished merely by inserting portions 192 and 194 into the holes 186.

As one of the primary objects of the invention is to provide a breaker point unit which is pre-timed and adjusted, fixtures are provided whereby a distributor and breaker point plate 1% and breaker points may be preadjusted separately yet will be properly related when assembled. In order to accomplish preadjustment of both the distributor and the breaker point plate components it is necessary to either assemble the plate 166 and distributor together, achieve the proper adjustment and remove the plate for later use or employ a pair of fixtures representing the distributor components, properly relate the fixtures to each other and then employ the fixtures to separately orient the distributor and plate 106 components whereby these members will be properly related and timed when the plate 196 is installed in the distributor.

Pre-timing of the breaker point plate 106 and breaker point assembly 108 may be accomplished on a fixture as shown in FIGS. l7-19 which includes a base element 290 on which is mounted a plate 202 mounting a pin 2'94 and a central recess 2%. A rotatable shaft 208 is centrally journaled in base 201} and mounts key pin 210 and a selectively positionable handle 212 extending from a slot within base 2%. Set screws 214 accurately limit movement of the handle within the slot. A scale 216 is afiixed to the base beneath the handle and an indicator atfixed to the handle212 enables the degrees of rotation of the handle and shaft 208 to be determined. A small electric battery 218 may be housed within base 299 and one terminal of the battery is afiixed to a grounded light bulb 224 which is observable by the operator and the other terminal is affixed to a lead 222 which may be attached to the breaker point assembly circuit as shown in FIG. 17.

The breaker point plate 106 may be inserted over shaft 208 whereby the cam portion 126 projects into recess 2G6 and notch 128 is engaged by key pin 210 and the plate 166 rests upon plate 202 with the pin 204 extending through the slot 142 of tang 136. It will be appreciated that shaft 263, key pin 21%, plate 202 and pin 204 simulate the shaft portion 22, key projection 64, plate 83 and pin 164 respectively. Thus as handle 212 is oscillated the cam 112 will rotate and the breaker points will be opened and closed under the influence of the cam follower.

When the plate 196 is thus mounted on the fixture a feeler gage or, preferably, a dial indicator gage may be easily employed to sense the degree of breaker point contact opening as the cam is rotated such that the cam follower passes over the lobes of the cam. The adjustment screws of the breaker point assembly are adjusted in the conventional manner to increase or decrease the contact gap to the correct spacing.

To time the breaker point assembly 108 the handle 212 may be moved clockwise, FIG. 17, until the lowermost set screw 214 is engaged. At this point the relation between key pin 210 and pin 204 is the same as the relation of key projection 64 and pin 104 when the distributor is properly timed, e.g. the timing mark on the engine is aligned with the timing point thereof and the number one cylinder is coming in the compression stroke. With handle 212 in this position and the lead 222 connected to terminal 118 a screw driver or similar tool is inserted into the appropriate opening and twisted to deflect tang 136 horizontally and hence rotate plate 106 relative to cam 112 until the light 220 either goes off, if it was previously on, or goes on if it was previously off. Such adjustment of the tang 136 regulates the breaker points plate relative to the cam to that point where the electrical contact between the breaker point contacts is just broken. It is at this time that the secondary circuit opens and the spark plug voltage is released for ignition purposes in cylinder number one. Although the light circuit is disclosed as self contained within the fixture it will be understood that circuiting using outside power sources may be employed in a similar manner and bells, meters or other signal means may be used to indicate opening and closing of the breaker points.

The scale 216 and light 220 may also be employed to determine the characteristics of the cam. By rotating handle 212 and observing the dwell, e.g. the rotational movement of the cam during which the contacts are closed may be measured. Thus worn cams and contacts which have deformed due to pounding may be readily discovered and faulty operating characteristics analyzed.

The breaker point plate fixture includes a hold down finger 224, FIG. 18, which radially moves in a guideway in base 290 and is inwardly biased by a spring 226. The finger 224 is provided with a beveled edge 228 which overlaps plate 106 and holds the plates 106 and 202 in intimate contact.

It is, of course, necessary to properly time the engine distributor housing in relation to the engine piston operation and this may be done in several ways. For instance, a breaker point plate 106 which has been pretimed may be installed in the distributor, the engine started and by the use of a timing light the distributor housing may be rotated relative to the engine block until the timing indicia of the motor aligns under the timing light in the known manner. This procedure can be used only where a pre-timed breaker point plate is available and the engine is substantially timed, requiring only fine adjustment.

In assemblying new engines and distributors it is desired to employ a distributor timing fixture as shown in FIGS. 15 and 16 to minimize the time of assembly and to simplify the assembly procedure. This fixture includes a circular peripheral knurled hand gripped portion 230 having a bored downward extending hub 232 which may be slipped over the shaft portion 22. A sleeve 234 is mounted on the hub 232 and may be angularly adjusted thereto and locked by a set screw 236. A radial arm 238 is mounted on sleeve 234 and is provided with a hole 240 which receives pin 104. The lower end of hub 232 is formed with a radial notch 242 which cooperates with the key projection 64. It is the relation between notch 242 and hole 240 which is critical and determines the proper timing relationship between the engine block and drive shaft 16.

An adjustable arm 244 is rotatably mounted on sleeve 234 and is provided with a downward projecting flange 246 which engages the notch 247 in the rim of housing which orients the distributor cap on the housing. Arm 244 is locked in position by a thumb screw 24% projecting through an arcuate slot 250 in the portion 230. The arm 244 and flange 246 serve to orient the support plate 88 to the housing 10.

The distributor fixture is employed in the following manner: The engine timing ind-icia is aligned when the number one cylinder is coming on the compression stroke, the fixture is mounted on the distributor as shown in FIG. which holds the shaft 16, support plate 106 and housing 10 in the proper timing relation for ignition of the number one cylinder, the distributor is mounted in the engine block in engagement with the cam shaft drive gear, the distributor is rotated to take up any backlash or play in the cam shaft and gear train and thereupon the distributor flange 14 is clamped in position.

It will be understood that the fixture of FIG. "15 may be placed on the fixture of FIG. 17 to check or set the orientation of the two fixtures and that upon moving handle 212 to the full clockwise zero position the key pin 210 will align with notch 24 2 and the pin 204 aligns with the hole 240 in the proper timed relationship for the number one cylinder.

Thus the use of these fixtures permits rapid, accurate installation of the distributor on the engine block and permits the breaker point plate 106 and the components mounted thereon to be pro-adjusted before installation in the distributor wherein it is merely necessary to place the plate 106 in the distributor, connect the ground and secondary leads, actuate clamps 94 and replace the distributor cap to provide a completely assembled operating unit. One of the advantages of such a construction results from the ability of the breaker point plates to be stored in dust proof containers prior to installation in the distributor and the breaker points need not be installed until the final engine assembly operation when the distributor cap is affixed to the distributor. With conventional distributor constructions the breaker points often collected dirt, dust and grease during engine assembly and wiring resulting in earlier failure of the points.

It will be appreciated that the breaker point assembly may be adjusted on the plate 106 in the conventional manner without using the timing fixtures. With the plate 106 affixed to plate 88 the distributor may be timed in the conventional manner, the breaker point assembly 108 and condenser 110 may be removed from plate 106 and replaced by new components and adjusted for contact gap in the known manner. Thus, although servicing of the distributor will usually consist of replacing the entire plate 106 repairs may be made where only a breaker point assembly or condenser is available.

Constructing the cam, breaker points and condenser as a unit enables the average motorist to install a new unit himself and by carrying a suitable packaged spare breaker point plate unit in the vehicle many emergency ignition troubles may be quickly cured. Another advantage of the unit construction lies in the ability of the breaker points to be pro-adjusted by the manufacturer using the proper gages, etc. to insure that the contact gap is accurately set and the operation of the points and cam properly related. Breaker point plates which are removed from the distributor because of worn contacts may be reconditioned by afiixing thereto a new condenser and breaker point assembly and cam, if needed, which will reduce replacement costs.

Another advantage of the unit breaker point plate construction is illustrated in FIG. 14 wherein two breaker point assemblies 108 are mounted on the plate 106 to provide dual breaker point control of the ignition circuit. Improved ignition characteristics may be obtained by using two sets of points connected in parallel relationship whereby one set of points opens the primary circuit and the other set of points closes the circuit. The respective cam followers of the breaker point assemblies engage slightly different portions of the cam, one lagging the other approximately 7, which permits a longer coil buildup time and produces a better ignition spark at high speeds. In conventional distributors dual breaker points usually require a special distributor housing components and arrangement, however, dual breaker points may be installed in engines using the distributor of the invention merely by substituting the plate 106 having a single breaker point assembly thereon for a plate 106 having dual breaker points mounted thereto. Such ease of interchanging types of breaker points is of importance in new auto-mobile sales where dual breaker points are offered as optional equipment and may be quickly installed by the dealers mechanics.

It will thus be understood that the distributor of the invention discloses structural distinctions and relationships in the distributor art which provide a dependable, easily assembled and manufactured, economical and quickly serviced ignition distributor. Components such as the centrifugal advance are formed to prevent improper assembly and innovations such as the use of snap ring 26, inclined portions 70, bearing blocks 74, clamps 94, spring pin 172 and holes 136 combine to reduce materially the number of components and machining operations required in conventional distributor manufacture. The mounting of the breaker points, condenser and cam on a common plate to provide a quickly replaceable unit of the most frequently replaced distributor components simplifies replacement of these components to the extent that their installation may be achieved by the average motorist, permits postponement of the installation of the breaker points in new engine assembly until the distributor cap is installed eliminating the ohance of foreign matterfouling the points during engine assembly, minimizes vehicle outof-service time due to breaker point replacement, permits the breaker points to be factory timed and adjusted and permits quick interchange of single and dual breaker point assembly units.

It will be appreciated that the tang 136 and the adjusting thereof permit the angular relationship between the cam, when positioned for firing of the number one cylinder, and the breaker points cam follower to be very accurately adjusted to obtain optimum timing. The adjustable feature of the tang 136, or other locating element employed for the same purpose, is necessary to obtain accurate timing in that the variance of the dimensions of the mounting plate 106, cam 112, breaker points and locations of pin 104 and slot 142 due to manufacturing tolerances will result in each of the breaker point plate units varying slightly as manufactured and assembled, however, by adjusting tang 136 the individual distinctions of each unit may be eliminated and each unit may be standardized. Thus, once the distributor is properly positioned on the engine proper timing will be insured upon 11 placing plate 1% upon support plate 83 with the pin 1% projecting through slot 142. By providing adjusting and compensation means on the plate 106 itself each breaker point plate is standardized and eliminates any need to re-orient the distributor on the engine block when replacing the points.

The components mounted upon plate 1% may take forms other than those illustrated, for instance, bearings may be mounted on the plate to accurately rotatably support the cam on the plate itself or tie locating element may take forms other than tang 136 as any adjustable member affixed to plate 136 having a hole, pin or similar mating element could be used which would cooperate with a pin or hole in the support plate and diaphragm link arm. The disclosed construction is preferred as being of economical construction and dependable operation.

While the above description is limited to the illustrated embodiments it is intended that the invention be defined only by the spirit and scope of the following claims.

I claim:

1. In an internal combustion engine ignition system, including a distributor having a drive shaft and a rotatably mounted primary circuit contact support plate, the improvement comprising a replaceable pretimed breaker point assembly fixable to the support plate, said assembly including a mounting plate, means releasably affixing and adjustably relating said mounting plate to the support plate, a pair of breaker points mounted on said mounting plate, and cam means rotatably mounted on said mounting plate having clutch means defined there on for driving interconnection with the drive shaft, said cam means being rotated by the drive shaft and adapted to open and close said breaker points.

2. A pre-timed, pro-adjusted ignition breaker point unit for use with an internal combustion engine distributor having a drive shaft and a rotatably mounted support plate properly oriented to the drive shaft, said unit comprising a mounting plate, means formed on said mounting plate for cooperation with readily accessible clamping means mounted on the support plate, locating means formed on said support plate for cooperation with adjustable locating means formed on the mounting plate, a pair of breaker points mounted on said mounting plate, a cam rotatably mounted on said mounting plate adapted to be driven by the distributor drive shaft upon aifixing said mounting plate on the support plate and cam follower means operatively connected to said breaker points engageable by said cam.

3. A pre-timed, pre-adjusted ignition breaker point unit for use with an internal combustion engine distributor having a drive shaft and a rotatably mounted support plate regulated by automatic spark advance means, said unit comprising a mounting plate, means formed on said mounting plate for cooperation with readily accessible quick-release clamping means mounted on the support plate, locating means formed on said support plate for cooperation with adjustable, pre-set locating means formed on the mounting plate, a pair of breaker points mounted on said mounting plate, a condenser affixed to said mounting plate connected in parallel with said breaker points and a cam rotatably mounted on said mounting plate adapted to be driven by the drive shaft and means engaging said cam adapted to actuate said breaker points upon rotation of said cam.

4. In an engine ignition system including a distributor having a drive shaft driven in timed relation to the engine and a rotatably mounted support plate, a pre-timed, preadjusted breaker point unit comprising a mounting plate removably mounted on the support plate, means adjustably locating said mounting plate to the support plate, a pair of breaker points mounted on said mounting plate, a cam rotatably mounted on said mounting plate adapted to be driven by the distributor drive shaft upon affixing said mounting plate on the support plate and cam follower 12 means operatively connected to said breaker points engageable by said earn.

5. In an ignition system including a distributor having a drive shaft and a rotatably mounted support plate operatively interconnected with automatic spark advance means for rotation thereby, a pre-timed, pre-adjusted replaceable timing unit including a mounting plate angular- 1y adjustably mounted on the support plate and common means connecting the spark advance means to said support plate and angularly adjusting said mounting plate to the support plate.

6. In an ignition distributor having a drive shaft, a drive sleeve rotatably mounted on said drive shaft, centrifugal governor spark advance structure drivingly connecting said shaft and said sleeve, said structure including a weight supporting plate aflixed to said shaft, first and second weights pivotally mounted on said plate in opposing re lationship to said shaft, first and second stud means affixed to said first and second weights respectively, a spark advance plate affixed to said drive sleeve, first and second slot means defined in said spark advance plate to receive said first and second stud means respectively, the dimensions of said first stud and slot means being greater than said second stud and slot means whereby said second slot will not receive said first stud and spring means interposed between said weights and said supporting plate.

7. In an ignition distributor as in claim 6 wherein said spring means comprise first and second springs of different tension characteristics interposed between said first and second weights respectively and first and second spring anchorages formed on said weight supporting plate, said first anchorage adapted to receive only said first spring and said second anchorage adapted to receive only said second spring.

8. In an ignition distributor as in claim 6 wherein adjustable abutment means are mounted on one of said weights and are adapted to abut said weight mounting plate limiting pivotal movement of said weight.

9. In an ignition distributor having a housing, a drive shaft and means rotatably supporting a pair of breaker point contacts, said means including a bearing block mounting plate affixed within the housing, said bearing block mounting plate having a central opening defined therein concentric to the drive shaft, a plurality of bearing blocks mounted on said plate adjacent said opening, at least one of said bearing blocks being radially movable on said plate, means biasing said movable block outwardly, an outwardly facing undercut surface formed on each of said blocks, a breaker point mounting plate support plate having a central circular opening having a beveled periphery defined therein, said undercut surfaces being adapted to engage said beveled periphery whereby said support plate is rotatably mounted on said bearing blocks.

10. In an ignition distributor as in claim 9 wherein said bearing block mounting plate rests upon a shoulder defined in the housing and downward outwardly extending portions are formed on said mounting plate adjacent the housing whereby fastening means extending through the housing may engage said portions to hold said plate on said shoulder.

11. In an ignition distributor, a housing, a drive shaft rotatably supported within said housing, rotatably mounted breaker points within said housing and vacuum operated spark advance means adapted to rotate said breaker points about the axis of the drive shaft, the improvement comprising a recess formed in said housing, a protuberance formed on the Vacuum operated spark advance means housing complementary to said recess and receivable therein, a pin passing through said distributor housing, recess, and protuberance to afiix said vacuum advance means to the distributor, said vacuum advance means including an axially movable link extending through said protuberance into said housing, an axial extending slot defined in said link, said pin passing through 13 said slot whereby said slot and pin limit the axial movement of said link.

12. In an ignition distributor having a drive shaft and a primary circuit contact support plate, the improvement comprising a replaceable breaker point mounting plate aifixable upon said support plate, a pair of breaker point-s affixed on said mounting plate, a condenser aifixed on said mounting plate connected in parallel with said breaker points, a cam rotatably supported on said mounting plate adapted to open and close said points indirectly driven by said drive shaft, a deflectab'le tang formed from a portion of said mounting plate, a hole define-d in said tang and a pin mounted in said support plate adapted to align with and project through said hole upon proper orientation of said mounting plate to said support plate.

13. In an internal combustion ignition distributor including a housing and a cap mounted on said housing, retaining means maintaining the cap on the housing, said retaining means comprising a spring clip of elongated, bowed free form, one end of said clip being formed with a portion adapted to engage the cap, the other end being formed with a first portion bent back toward but less than 180 to a second adjacent portion and spaced therefrom, a recess defined in said housing adapted to receive said first and second portions and of such dimension as to deflect said first spring clip portion toward said second portion during insertion and abutment means within said recess adapted to engage the free end of the said first portion to prevent said clip from being withdrawn from said recess.

14. -In an internal combustion engine ignition distributor including a housing and a cap mounted on said housing, retaining means maintaining the cap on said housing, said retaining means comprising a spring clip of elongated bowed for-m, one end of said clip being formed to engage the cap, the other end of said clip comprising a double bent portion deformed at least 90 back in the direction of the bowed intermediate clip section, said double bent portion comprising first and second portions, said first portion being bent back more than 90 and less than 180 with respect to said second portion to define an acute angle therewith, a recess defined in said housing opening in a direction away from said cap adapted to receive said double bent portion and dimensioned as to deflect said first portion toward said second portion during the insertion into said recess and abutment means within said recess adapted to engage the free end of said first portion to prevent said double bent portion from being withdrawn from said recess.

15. A fixture for orienting an ignition distributor to an engine block wherein the distributor includes a drive shaft, key means rotated by the drive shaft, a support plate mounted within the distributor and locating means mounted on the support plate, said fixture comprising first means adapted to engage and cooperate with the key rotated by the drive shaft and second means pro-determinedly related to said first means cooperating with the support plate locating means whereby the drive shaft and support plate may be held in a pre-determined relationship while the distributor is assembled to the engine block.

16. A fixture for pre-adjusting and pre-timing an ignition breaker point unit comprising a mounting plate, a pair of breaker points adjustably mounted on said plate, a cam rotatably supported on said plate having key cooperating means engageable with a distributor drive shaft driven key, an adjustable locating means mounted on said plate and a cam follower operatively interconnecting said points and cam, said fixture comprising a key engageable with the cam key cooperating means for orienting the cam to said fixture and locating means mounted on said fixture in pre-determined relation to said fixture key for cooperation with the locating means of the mounting plate, and a test circuit including said plate, breaker points and indicating means employed in conjunction with said fixture whereby said plate mounted locating means may be ad justed to rotate said breaker points about said cam until the breaker points slightly break contact.

17. A fixture for pro-adjusting and pre-timing an ignition breaker point unit as in claim 16 wherein means are provided for rotating said fixture key whereby the cam may be rotated to open the breaker points to a maximum opening for pre-adjusting the breaker point gap.

18. An internal combustion engine ignition distributor comprising, in combination, a distributor housing, a rotatable drive shaft within said housing having a cam driven thereby, a rotatably mounted support plate within said housing, spark advancing means mounted on said housing, means interconnecting said spark advancing means with said support plate for producing rotation of said plate, a pretimed breaker point mounting plate mounted on said support plate, means releasably mounting said mounting plate on said support plate, interacting locating means defined on said plates orienting said mounting plate to said support plate in predetermined relation, a breaker point assembly mounted on said mounting plate including cam follower means operatively engaging said cam, and means adjustably mounting said breaker point assembly on said mounting plate.

References Cited in the file of this patent UNITED STATES PATENTS 1,584,881 Mallory May 18, 1926 2,008,647 Schneider July 16, 1935 2,187,070 Arthur Jan. 16, 1940 2,643,304 Lautzenhiser June 23, 1953 2,688,055 Schneider et a1 Aug. 31, 1954 2,704,395 Heidegger Mar. 22, 1955 2,713,096 Brunk July 12, 1955 2,717,286 Bales Sept. 6, 1955 2,722,049 Turlay Nov. 1, 1955 2,769,047 Hartzell et al. Oct. 30, 1956 2,801,304 Winkley July 30, 1957 2,847,524 Slick Aug. 12, 1958 2,889,418 Kline June 2, 1959' 2,929,888 Hagmaier et a1 Mar. 22, 1960 2,965,726 Norris et al. Dec. 20, 1960 2,991,338 Mason July 4, 1961 FOREIGN PATENTS 747,644 France Apr. 4, 1933 

1. IN AN INTERNAL COMBUSTION ENGINE IGNITION SYSTEM, INCLUDING A DISTRIBUTOR HAVING A DRIVE SHAFT AND A ROTATABLY MOUNTED PRIMARY CIRCUIT CONTACT SUPPORT PLATE, THE IMPROVEMENT COMPRISING A REPLACEABLE PRETIMED BREAKER POINT ASSEMBLY FIXABLE TO THE SUPPORT PLATE, SAID ASSEMBLY INCLUDING A MOUNTING PLATE, MEANS RELEASABLY AFFIXING AND ADJUSTABLY RELATING SAID MOUNTING PLATE TO THE SUPPORT PLATE, A PAIR OF BREAKER POINTS MOUNTED ON SAID MOUNTING PLATE, AND CAM MEANS ROTATABLY MOUNTED ON SAID MOUNTING PLATE HAVING CLUTCH MEANS DEFINED THEREON FOR DRIVING INTERCONNECTION WITH THE DRIVE SHAFT, SAID CAM MEANS BEING ROTATED BY THE DRIVE SHAFT AND ADAPTED TO OPEN AND CLOSE SAID BREAKER POINTS. 